Our data show that iNK T cells are pathogenic in IAS, and that T helper type 2 (Th2) polarization of iNK T cells using the synthetic glycolipid OCH significantly Maraviroc price reduces mortality from IAS. This reduction in mortality is associated with the systemic elevation of the anti-inflammatory cytokine interleukin (IL)-13 and reduction of several proinflammatory cytokines within the spleen, notably interleukin (IL)-17. Finally, we show that treatment

of sepsis with OCH in mice is accompanied by significantly reduced apoptosis of splenic T and B lymphocytes and macrophages, but not natural killer cells. We propose that modulation of iNK T cell responses towards a Th2 phenotype may be an effective therapeutic strategy in early sepsis. “
“An immunomodulatory extract (AndoSan™) based on the medicinal mushroom Agaricus blazei Murill (AbM) has shown to reduce blood cytokine levels in healthy volunteers after 12 days’ ingestion, pointing to an anti-inflammatory effect. The aim was to study whether AndoSan™ had similar effects on cytokines in patients with ulcerative colitis (UC) and Crohn’s disease (CD). Calprotectin, a marker for inflammatory bowel Staurosporine concentration disease (IBD), was also measured. Patients with CD (n = 11) and with UC (n = 10) consumed 60 ml/day of AndoSan™. Patient blood plasma was harvested before and after 6 h LPS (1 ng/ml) stimulation ex vivo. Plasma and faecal calprotectin levels were analysed using ELISA and 17 cytokines [IL-2, IFN-γ, IL-12 (Th1), IL-4,

IL-5, IL-13 (Th2), IL-7, IL-17, IL-1β, IL-6, TNF-α, IL-8, MIP-1β, MCP-1,

G-CSF, GM-CSF and IL-10] by multiplex assay. After 12 days’ ingestion of AndoSan™, baseline plasma cytokine levels in UC was reduced for MCP-1 (40%) and in LPS-stimulated blood for before MIP-1β (78%), IL-6 (44%), IL-1β (41%), IL-8 (30%), G-CSF (29%), MCP-1 (18%) and GM-CSF (17%). There were corresponding reductions in CD: IL-2 (100%), IL-17 (55%) and IL-8 (29%) and for IL-1β (35%), MIP-1β (30%), MCP-1 (22%), IL-8 (18%), IL-17 (17%) and G-CSF (14%), respectively. Baseline concentrations for the 17 cytokines in the UC and CD patient groups were largely similar. Faecal calprotectin was reduced in the UC group. Ingestion of an AbM-based medicinal mushroom by patients with IBD resulted in interesting anti-inflammatory effects as demonstrated by declined levels of pathogenic cytokines in blood and calprotectin in faeces. The Agaricus blazei Murill mushroom (AbM) (jap.: Himematsutake) of the Basidiomycetes family grows wildly in the coastal Piedade area outside of São Paulo, Brazil. People in this area have traditionally used AbM as a health-food ingredient. The frequency of serious diseases like atherosclerosis, hepatitis, hyperlipidaemia, diabetes and cancer [1] was lower in Piedade than in neighbouring regions, supposedly because of the AbM intake. In 1966, the mushroom was taken to Japan and introduced to the health-food market, and later AbM was also subjected to an increasing research effort.

15.2) mAbs or isotype-matched controls (all from eBiosciences). Fluorescence was analyzed on a FACSaria cytofluorometer (Becton Dickinson, Erembodegem, Belgium) and results were analyzed using the Flowjo software (Tree Star, Ashland, OR). Three days after irradiation, mice were injected s.c. with 500 μg BSA or OVA in the absence or presence 10 μg CpG-ODN, 1 μg GM-CSF and 1 μg sCD40L. For ex vivo experiments, spleen cells were isolated one day later and cocultured with OT-1 CD8+ T cells

for 18 h (cell ratio 1:2). T-cell activation was evaluated by quantifying IL-2 and IFN-γ by ELISA (BD Pharmingen, San Diego, CA) in the supernatants. For in vivo experiments, mice were injected i.v. one day later with 2×106 CFDA-SE-labeled check details OT-1 CD8+ T cells. Spleen and draining LN cells were collected two days later and the proliferation OT-1 CD8+ T cells was determined by evaluating CFDA-SE staining

Bortezomib ic50 by FACS. To evaluate in vitro the cross-presentation activity of microglia, CD11b+ CNS cells were isolated three days after irradiation, incubated for 8 h with 100 μM BSA or OVA. Then, 1×105 CD11b+ CNS cells were cocultured with 2×105 OT-1 CD8+ T cells for 18 h. T-cell activation was evaluated by quantifying IL-2 and IFN-γ by ELISA in the supernatants. To evaluate ex vivo and in vivo cross-presentation activity of microglia, mice were intracranially injected with 200 μg OVA or BSA (+/−10 μg CpG-ODN, 1 μg GM-CSF and 1 μg sCD40L), three days after irradiation. For ex vivo assay, CD11b+ CNS cells were magnetically sorted the day after and incubated with OT-1 CD8+ T cells

(cell ratio 1:2) for 18 h. T-cell activation was evaluated by quantifying IL-2 and IFN-γ by heptaminol ELISA in the 24 h culture supernatants. For the in vivo assay, mice were additionally injected the day after with 2×106 CFDA-SE-labeled OT-1 CD8+ T cells in the brain. CNS cells were collected two days later for FACS analysis. CD11b+ cells were analyzed for CD11b, H2-Kb, I-Ab, CD80 and CD86 staining. OT-1 CD8+ T-cell proliferation was evaluated by FACS analysis of CFDA-SE labeling. OT-1 CD8+ T-cell activation was evaluated by quantifying IFN-γ production, using the mouse IFN-γ secretion assay kit (Myltenyi Biotec). Briefly, brain cells were incubated 3 h with the OVA peptide SIINFEKL (Affiland), 10 min on ice in the presence of mouse IFN-γ catch reagent, before additional 45 min incubation at 37 °C in RPMI medium. Cells were then labelled for 10 min on ice with the allophycocyanin IFN-γ detection reagent. Cell flourescence was analyzed by flow cytometry. Data are shown as mean ± SD and were analyzed by the Student’s t test to reveal significant differences (*p < 0.05; **p < 0.005; ***p < 0.0005). GraphPad Prism 5.0 software (GraphPad Software, San Diego, CA) was used for all statistical analyses.

They produce high levels of IFN-γ and tumor necrosis factor-α (TNF-α), and can kill infected cells through the release of granzymes and perforin into the immunological synapse [60]. The cytokines IL-2 and IL-12 drive effector CTL differentiation by triggering STAT4 and STAT5 signaling, as well as through the phosphoinositide-3-kinase–Akt–mTOR and the rat sarcoma (RAS)-rat fibrosarcoma (RAF)–mitogen-activated protein kinase (MAPK) pathways [61]. After resolution of infection, the bulk of CD8+ T cells die; however, a small Maraviroc cell line fraction remains as long-lived memory CD8+ T cells that respond to re-exposure to the cognate pathogen with strong proliferation and rapid conversion into

effector cells. Already at early stages of the response, phenotypic and functional markers help to distinguish between short-lived effector

CTLs and T cells that can give rise to long-lived memory cells. The CD44hiCD62Llokiller cell lectin-like receptor 1(KLRG1)hiIL7-Rαlo phenotype is characteristic for effector CTLs, whereas the memory precursors can be defined as CD44hiKLRG1loIL7-Rαhi. The differentiation of naïve CD8+ T cells into effector and memory CTLs is regulated by balanced expression of several transcription factors. Whereas BCL-6, selleck compound eomesodermin (EOMES), inhibitor of DNA-binding (ID) 3 and T-cell factor 1 (TCF1) are associated with memory cell differentiation and longevity, T-BET, ID2, and BLIMP-1 promote effector cell development [60]. Like in Th17 cells, TGF-β selleck inhibitor acts in combination with IL-6 or IL-21 to promote differentiation of IL-17-producing and ROR-γt-expressing Tc17 cells, which are detectable during viral infections, autoimmunity, and in tumor environments. Tc9-cell development parallels that of Th9 cells and is also induced by TGF-β and IL-4. These cells are detectable in the lamina propria of mice and in the periphery of mice and humans with atopy [62, 63]. In contrast

to CTLs, Tc9 and Tc17 cells display low cytotoxic activity [63-68]. Three recent studies demonstrated essential roles for IRF4 in effector CTL development. Although dispensable for initial activation and proliferation, IRF4 was required for CTL expansion, sustained expression of the effector CTL phenotype, and function. This was shown in three experimental models of infection with intracellular pathogens, namely in mice infected with lymphocytic choriomeningitis virus (LCMV), influenza virus, and L. monocytogenes [22, 23, 25]. Although WT mice can clear infection with L. monocytogenes within 10 days, Irf4–/– mice failed to clear the bacteria. This was caused by defective CD8+ T-cell function that was T-cell intrinsic, as transfer of WT CD8+ T cells into Irf4–/– mice rescued bacterial clearance [23]. Furthermore, mice with conditional deletion of IRF4 in CD8+ T cells failed to control influenza infection [25]. Similarly, defective CTL development in the absence of IRF4 was shown in response to infection with LCMV [22, 69].

Lytic-activity of cCTLs was assessed after 3–4 stimulations in a [51Cr]-release-assay [39, 40]: Target cells were labelled with 100 μCi [51Cr] for 1.5 h (37 °C) in dog-serum, washed and resuspended in X-Vivo15. [51Cr]-labelled target cells (2000 cells/well) were incubated with effector cells for 4 h (37 °C; E:T = 80:1) in 96-well-microtiter plates. Radioactivity of FK506 culture-supernatant was measured by a γ-counter and percentage of specific-lysis

(cytotoxicity) was calculated:% cytotoxicity = (experimental release-spontaneous release)/(maximum release-spontaneous release) × 100. For the blocking-experiments, we used the monoclonal human canine-cross-reactive MHC-I antibody (clone G46-2.6, end-concentration of 40 μg/ml, BD, Heidelberg, Germany). Canine-IFN-γ-ELISPOT assay (R&D-Systems, Minneapolis, MN, USA) used to quantify peptide-epitope-specific, IFN-γ-releasing effector cells, performed according to the manufacturers’ instructions and examined on day 21 or 28 of T cell stimulation. Precursor frequency of cUTY-specific T cells in dogs’ peripheral blood was evaluated on day 0. Spots were counted by visualization using a dissecting-microscope.

For selleck kinase inhibitor the blocking-experiments, we used the monoclonal human canine-cross-reactive MHC-I antibody (clone G46-2.6, end-concentration of 40 μg/ml, BD). In vivo generation of hUTY-specific-CTLs was tested by immunizing a female dog with PBMCs from a DLA-identical-male dog. On day 0, 50 ml heparinized peripheral-blood was taken from the male-donor

and PBMCs were isolated as described above. 2.5 × 108 cells were resuspended (5 ml warm-RPMI1640) and applied in equal-amounts subcutaneously to the four limbs, followed by a second-immunization on day 14. There, PBMCs (3.2 × 108 in 20 ml RPMI1640) were injected intravenously with 100 ml NaCl. 35 days after the second-injection, blood-derived T lymphocytes were harvested and studied for their UTY-specific reactivity. Distribution of the different cell-populations was monitored at day 0, 14 and 35 via flow-cytometry (donor and Non-specific serine/threonine protein kinase recipient). Mean- and standard-deviation were performed using microsoft® excel xp, and Statistical-calculations were achieved using spss-Version 11.5 (SPSS, Chicago, IL, USA). A statistical significance was accepted for P ≤ 0.05. Canine-female-UTY-specific CTLs were induced in vitro using autologous-DCs derived from monocytes of healthy female dogs (#1, #4, #6). DCs were pulsed with the identified HLA-A2-binding hUTY-derived peptides W248, T368 and K1234. T cells decreased during the first 2 weeks of stimulation, but then the surviving T cells proliferated, resulting in a 1.5-2.9-fold percentage-increase of successfully expanded cCTLs (Fig. 1), whereas the amount of CD4+ T cells decreased (1.6–2.9-fold; data not shown). That means that the absolute T cell number increased after 3–4 weeks of in vitro culture.

Direct sequencing of all fragments was carried out in an automatic sequencer. All sequence variations identified were verified on the complementary strand using an independent PCR product. Multiplex ligand-dependent probe amplification (MLPA) technique for mutations in the RPS19 gene.  Selleck GSI-IX The MLPA technique, which is used for the detection of complete or partial gene deletions or duplications, was carried out [13,14]. This technique is

based on the simultaneous hybridization and ligation of several probes matched to single exons using a single reaction tube, which is followed by PCR and analysis by capillary electrophoresis. Reduced peaks suggest deletions (even on only one exon of a single allele) and enhanced peaks suggest duplication [14]. Informed consent for genetic testing was obtained from the patient and the study was approved by the Trust’s Research and Development Department. Results of genetic analyses.  No loss-of-function mutations were identified in RPS19,

RPS24, RPS17, RPS5, BAY 80-6946 in vivo RPL11 and RPL35a genes that is in keeping with approximately 50% of cases of DBA where no mutations are found in these genes (RPS: ribosomal protein small subunit; RPL: ribosomal protein large subunit). However, heterozygous polymorphisms were identified in RPS24 and RPS17 genes: RPS24 IVSI +26 (c > t); RPS17 IVS2 −73 (g > c), IVS2 −30 (c > t) and nt159 T > C; and homozygous polymorphisms were identified in RPL11 gene: RPL11 −17 (c > g) and IVS5 +39

(a > g) (Fig. 2). The MLPA technique did not reveal any deletion (complete or partial) or duplication in the RPS19 gene (Fig. 3). Implications.  This illustrates a ribosomopathy in a patient with DBA (anaemia, raised adenosine deaminase levels) who subsequently developed CVID. She was dependent on corticosteroids and blood transfusions but went into remission at the age of 6 years. The current definition of ‘remission’ is stable, physiologically acceptable haemoglobin maintained for a minimum of 6 months without corticosteroids, transfusions or other therapy [15]. T cell responses to mitogens were suboptimum, as in a previous case of DBA, which also showed failure of T cell proliferation to human PRKACG recombinant interleukin (rIL)-2 [16]. Our patient therefore resembles approximately half of DBA patients who do not have mutations in the currently described six ribosomal genes (RPS19, RPS17, RPS24, RPL5, RPL11 and RPL35a), but the laboratory abnormalities (anaemia, raised eADA levels) suggest that other genes affecting ribosomal functions may be involved. A recent paper has described mutations in other genes, RPS7, RPS27A, RPL36 and RPS15, evident in DBA, but we have not looked for mutations in these genes [8].

Late (CD45RA+CD28–) effector CD8 cells express CD146. Collectively, these findings suggest two

modes of CD146 expression: one that is related closely to recent or chronic memory T cell activation and predominates in healthy donor CD4 T cells, and another, which appears to be more stochastic and predominates in the CD8 subset. Consistent with previous reports [11], circulating T cells in patients with sSS were phenotypically activated (increased CD25, OX40, and perhaps CD69), both in the CD4 and the CD8 subset. The increased frequency of CD146-expressing CD4 and CD8 cells in these patients, as well as the correlation with several activation markers, is consistent with this. Combinatorial analysis of activation markers Panobinostat supplier including CD146 may improve the assessment of T cell activation in CTDs. Importantly, CTD patients in general maintain normal or slightly reduced lymphocyte counts in blood [10, 11]; PBMC yields (by haemocytometer counting) were not markedly abnormal in our CTD patients. Unexpectedly, activation markers were not increased in T cells

from our SLE and most pSS patients. This contrasted with previous studies, in which increased frequencies of recently and chronically activated and senescent T cells were found in patients with SLE [10] buy ICG-001 or pSS [34-37], including patients studied by us (C. Bryson, F.C. Hall, unpublished observations). Most of the patients examined in the present study lacked critical organ involvement and had mild or moderate disease activity. Their disease was well controlled by drug therapy, ranging from hydroxychloroquine alone to various combinations of anti-proliferative agents, corticosteroids and biologicals (Supporting information, Table S1). This might account for their non-activated peripheral T cell phenotypes and low CD146 expression. This is not a sensitivity issue, as we detected T cell activation and CD146 up-regulation in sSS, and more recently in a separate study of patients with inflammatory arthritis, using the same reagents and protocols (C. Wu, R. Busch, J.S.H. Gaston, unpublished data). As a result of the unexpected non-activated

phenotypes in these patients, this study cannot address whether CD146 up-regulation is a disease-specific feature of sSS or a consequence Microtubule Associated inhibitor of systemic hyperactivity, which happened to be detectable only in sSS patients in our study. The latter explanation is, however, both more conservative and plausible. A much larger multivariate analysis of CTD patients with diverse diagnoses, varying in T cell activation, would be required to address this fully and to account for confounding variables. Our unpublished work (C. Wu et al.) also confirms previous findings (cf. Introduction) that CD146+ CD4 cells are strongly enriched for Th17 cells [CCR6+, CD161+; mitogen-stimulated interleukin (IL)-17 and IL-22 secretion].

0%, 63.6%, 50.4% and 87.3% respectively (Table 3). However, looking closer to the genus and species identification, differences between dermatophytes and Candida spp. were evident. Almost all dermatophytes which were positive

in culture could be identified by multiplex PCR (Table 3) achieving diagnostic sensitivities of more than 87.3% at the species and more than 88.6% at the genus level. In contrast to this finding, only 62.7% of culture positive Candida spp. were identified by Tyrosine Kinase Inhibitor Library manufacturer multiplex PCR. Furthermore, multiplex PCR revealed positive results with samples which were negative in culture. Especially, 38 T. rubrum and 12 T. interdigitale were additionally identified (Table 4). DNA preparations from these dermatophyte positive samples were amplified in multiplex PCR 2 by a genus- and a species-specific primer pair (Fig. 1b). The results for dermatophytes were further confirmed by other monoplex PCR using primer pairs as described in literature (data not shown).[1, 20-22] Taking into account that only 44.8% of microscopically positive samples could be confirmed by culture, the best reference standard

for truly positive samples is combining samples being positive in direct microscopy, culture or by both methods.[23] When applying this criterion, sensitivity, specificity, PPV and NPV of 87.3%, selleck chemicals 94.3%, 87.3% and 94.3%, respectively, were calculated for dermatophytes (T. rubrum, T. interdigitale and E. floccosum). The corresponding values for Candida spp. were 4-Aminobutyrate aminotransferase 62.7%, 93.5%, 77.8% and 87.4% respectively. The sample which was positive for Mucor spp. in culture was clearly genotyped as T. rubrum. Likewise, all samples which yielded Cryptococcus spp. or Trichosporum spp. by microbial growth were detected positive in multiplex PCR due to their companion fungus for which they were positive in culture, too. According to the geographical area, there are different characteristics and significant changes in epidemiology of dermatomycoses within the last decades.[1-3] In a recent study, Nenoff

et al. [5, 24] reported on the prevalence of onychomycosis pathogens isolated between 2008 and 2009 in eastern states of Germany. Our culture and multiplex PCR results are with regard to dermatophytes and S. brevicaulis in close agreement with the findings of these authors (Table 4). However, Candida spp. were detected in our study more frequently. This may be explained by the heterogeneity of the clinical manifestations within our study which besides onychomycosis also included mucosal and other skin infections. A predominance of C. parapsilosis and C. albicans was shown in candidal cultures and reflected the outcome of other published studies about superficial and mucosal candidoses.[8-10, 25] An accurate and rapid detection of fungi is most important for the success of treatment of dermatomycoses as clinical symptoms are shared with many other skin diseases.

Several studies demonstrated that polarization Saracatinib clinical trial of Th17 cells, in addition to Th1 cells, can profoundly accelerate the perpetuation of IBD.[18] On the contrary, switching of a Th1/Th17 profile to the enhancement of Treg cells or inhibition

of Th17 polarization is beneficial for restraining immune response and ameliorating intestinal inflammation.[19-21] The immunophilin ligand sirolimus, a macrolide antibiotic produced by Streptomyces hygroscopicus, exhibits potent immunosuppressive properties and is used therapeutically in countering autoimmunity and preventing allograft rejection.[22, 23] Specific inhibition by sirolimus of the serine/threonine protein kinase mammalian target of rapamycin (mTOR) in T cells blocks co-stimulation and cytokine-induced signalling but allows T-cell receptor-mediated signal transduction.[24] Consequently, sirolimus promotes T-cell anergy and deletion.[25, 26] Unlike other commonly used immunosuppressants, such as cyclosporine A and FK506, sirolimus does not appear to interfere with tolerance induction[27, 28] and permits the in vitro proliferation and suppressive function of Treg cells.[29, 30] Whether sirolimus influences the imbalance between Th17 and Treg cells in the development of IBD, however, has not been fully elucidated. In this study, we investigated the immunomodulatory effect of sirolimus in a 2,4,6-trinitrobenzene

check details sulphonic acid (TNBS) -induced murine colitis model. We also explored the potential mechanisms involved, especially in the balance of Treg and Th17 cells. Male BALB/c mice (8–10 weeks old) were purchased from the Center of Experimental Animals of Guangdong Province, and maintained at an animal facility under pathogen-free conditions. All studies involving mice were approved by the Guangdong Pharmaceutical University Animal Care and Use Committee. Colitis was induced by administration of TNBS in mice at day 0 as described previously.[31] In brief, mice were anaesthetized lightly, and a 3·5-F catheter was inserted intrarectally to 4 cm proximal to the anus. To

induce colitis, 120 μl 2·5 mg TNBS (Sigma-Aldrich, St Louis, MO) in 50% ethanol was injected slowly into the lumen via the catheter. Control MycoClean Mycoplasma Removal Kit mice received the same volume of 50% ethanol alone. To study the therapeutic effect of sirolimus, 1·25 mg/kg sirolimus (LC Laboratories, Woburn, MA) was administered intraperitoneally for three consecutive days starting at day 0 after TNBS administration. Animals were monitored daily for appearance of diarrhoea, loss of body weight and survival. The disease activity index was used to assess the grade of colitis based on a previously published scoring system by Reinecke et al.[31] All of the mice were killed at the indicated time after administration of TNBS. Colonic morphology was evaluated as a gross indicator of colitis.

2b), as detected by SDS-PAGE. Strikingly, there was only minimal loss of binding of the AMCA-HA peptide to HLA-DR1 upon digestion with CatG, and this slight loss was unaffected by the CatG inhibitor (Fig. 2c). Thus, peptide-loaded HLA-DR molecules are susceptible to CatG proteolysis, and cleavage of the β chain does not disrupt the integrity of the antigen-binding groove occupied by the peptide. To determine

the exact CatG cleavage site within the HLA-DR β chain, we performed N-terminal sequencing as well as peptide mapping Staurosporine supplier of the digestion products of purified soluble HLA-DR1 (sDR1). For these experiments we used sDR1 expressed in either insect cells or E. coli. Neither of these have a transmembrane domain and E. coli purified sDR1 is not glycosylated, which led to the fragments being smaller on gels (10 and 15 kDa). sDR1 expressed in insect cells (not shown) was used for identification of the N-terminal sequence of both fragments by Edman degradation (underlined italic sequence, Fig. 3a). The first residue of the larger fragment corresponds to the glycine (G) in position 1 of the mature protein. The first residue of the smaller fragment was selleck kinase inhibitor identified as glutamine (Q) at position 110. In order to define the boundaries

of both fragments, we also digested sDR1 expressed in E. coli (Fig. 3a), which is not glycosylated and was therefore used for MALDI-TOF analysis. The two bands were excised from a gel and digested with trypsin, Staphylococcus aureus V8 protease, or Arg-C protease. All peptides of these digests identified by mass spectrometry are indicated in black text in Fig. 3a. The peptide SFTVQRRVEPKVTVYPSKTQPL (underlined in Fig. 3a) was identified from a V8 digest and the peptide RVEPKVTVYPSKTQPL was identified from an Arg-C digest of the larger fragment, indicating that CatG did not not cleave after the arginine (R), but did cleave after leucine 109 (L109). Based on the masses of the two fragments and on the fact that their sequences were contiguous, these fragments appear to represent the complete β chain, which therefore has only a single CatG cleavage site. The cleavage site, between HLA-DRβ L109 and glutamine 110 (Q110,

L/Q), is located on a loop between fx1 and fx2 of the membrane-proximal, immunoglobulin-like domain, as indicated on the crystal structure of HLA-DR (Fig. 3b). To explore whether HLA-DR β chain polymorphism might influence CatG susceptibility, we first compared the amino acid sequences of several HLA-DR β chains [DRB1*0101 (DR1), DRB1*1501 (DR2b), DRB1*0301 (DR3), DRB1*0401, and DRB1*0404] and found conservation of the L/Q cleavage site (Fig. 4a). We then subjected various recombinant soluble HLA-DR allelic variants to digestion with CatG and used HLA-DR-specific rabbit serum (CHAMP) to measure residual levels of DRβ and detect the 18-kDa DRβ fragment (Fig. 4b). As predicted from sequence alignment, CatG degraded the β chain of all HLA-DR molecules tested.

In humans remission of Crohn’s disease patients was observed after human immunodeficiency virus (HIV) infection [6] and thymectomy was demonstrated to prevent relapse in ulcerative colitis (UC) patients [7].

In addition, a case study described cure of UC by excision of an invasive thymoma [8]. T lymphocytes are generated from haematopoietic stem cells in the bone marrow and become immunocompetent through a maturation process in the thymus, during which they are termed thymocytes. In the thymus they undergo negative selection, deleting self-reactive thymocytes Luminespib by apoptosis, thereby generating central tolerance. Our previous studies on the Gαi2-deficient mouse model of colitis, as well as mice with dextran sodium sulphate (DSS)-induced colitis, demonstrated aberrant thymocyte development with reduced frequencies of immature and increased frequencies of mature thymocytes before and during onset of colitis, as well as reduced migration towards intrathymic FDA-approved Drug Library manufacturer chemokines [9,10]. We therefore hypothesized that

similar abnormalities might also be present in human IBD. Due to the very limited access of thymic tissue from IBD patients, we used the technique of T cell receptor excision circle (TREC) analysis to investigate the relative abundance of recent thymic emigrants (RTE) in the periphery. Upon entrance into the thymus the thymocytes undergo rearrangement of their TCR genes, along with intense proliferation. T lymphocytes have four sets of TCR genes that will form either of two types of heterodimers: αβTCRs which are expressed by the majority of peripheral T cells, or γδTCRs, expressed by a subset of T cells mainly in the skin and intestinal epithelium [11]. The great diversity in the antigen-recognizing domains of the TCR molecules are generated by random combinations of multiple variable (V), diversity (D) and joining (J) gene segments (TCR δ and β chains), or V and J gene segments (TCR γ O-methylated flavonoid and α chains). V(D)J recombination

is initiated by the recognition of recombination signal sequences (RSSs) that flank the coding segments, and during this process the DNA located between the two RSS regions is circularized, forming an extrachromosomal circular excision product containing the two ligated RSS regions [11]. These so-called TRECs are stable and are not duplicated during mitosis, and are thus diluted-out with each cell division [12]. The levels of TRECs in naive T cells in peripheral blood are therefore a good measurement of thymic output. The method has been used extensively to study T cell reconstitution in highly active antiretroviral therapy (HAART)-treated HIV-patients [13] as well as after bone marrow transplantation following, e.g. myeloablative therapy for leukaemia [14].